Like those in the previous verses, and those in the verses following, here is yet another man mentioned in God's dispatches.
He is a hero/faith and yet even with engaging in many acts (v20) Benaiah did not match the greatness of the first three men.

As I read these short biographies, I can't help but feel myself to be a spiritual pygmy!
And yet such a feeling in itself has some very helpful aspects:

[i] It tends to keep us humble.
Worst thing any Christian can be afflicted with his pride.
Not to say that we are not to "attempt great things for God" (William Carey) so that we do not think highly of ourselves…
...but pride is an awful problem.
Some of the proudest people have the least to be proud about!   
Paul was a spiritual giant, and so he was given a thorn/flesh so that he would not (as a Pharisee was capable of doing)
"be exalted above measure" (2 Corinthians 12:7)

[ii] Such humility (Note, we do not say: humiliation) serves to have us appreciate that our standing with God in not dependent upon our servitude for him (whatever grade) but on the perfect, finished, all sufficient work of Jesus Christ.
As we mourn our failures again/again, often crying our like Paul (Romans 7:24) we can still rejoice that we are accepted in the victory/Christ.
In this…we are on the exact same plane as these mighties, even those in the front rank.

[iii] Such humility, coupled with a love for Jesus Christ (which is the mainspring for any effort for God) will encourage us to emulate these men. They show what can be done.
Often the reason why we are down in the lower ranks is because, despite our pious words, we are happy to linger down there and maintain those links we have and cherish with the world!
Here is our opportunity (again) to see: A purer form/serving God - that it can be done - and that it will not unnoticed.  

Think re: this man Benaiah. We want to concentrate (today) on his fight with the lion in the pit on a snowy day. 3 main points:

1) THE WORST POSSIBLE FOE:
a lion

The lion is rightly regarded as "the King/Jungle"
Noted for its strength/viciousness/fighting qualities

A/ An earlier ref/lion in Numbers 23:24
Behold, the people shall rise up as a great lion, and lift up himself as a young lion: he shall not lie down until he eat of the prey, and drink the blood of the slain.
(Spoken: The COI when in full flight against their foes)
The lion usually won its fights and did so with great ease.

B/ When God spoke/wrath He often portrayed himself as a lion:
For I will be unto Ephraim as a lion, and as a young lion to the house of Judah: I, even I, will tear and go away; I will take away, and none shall rescue him. (Hosea 5:14)
I will be unto them as a lion: as a leopard by the way will I observe them. I will meet them as a bear that is bereaved of her whelps, and will rend the caul of their heart, and there will I devour them like a lion: the wild beast shall tear them. (Hosea 13:7-8)
We are building up/picture of what a formidable foe the lion is.
Benaiah faced the worst possible enemy he could find.

C/ Helpful for us to learn something more about this brave man:

[i] Not/first mention: See 8:18/20:23 "Over the Cherethites and over the Pelethites" (Basically: Bodyguards. Head of security)
However, he had no bodyguards here when he fought the lion.

[ii] His name had a spiritual meaning: Means "Jehovah has built"
Significant: Reminds us: Psalm 127:1 Except the Lord build the house, they labour in vain that build it.
 
[iii] His stock was good. Son/Jehoiada: "Jehovah/knows"
His father was taught from earliest days to rest the knowledge which Jehovah has.
What comfort lies in this particular attribute of Jehovah.
He knows all things, even the hidden things/darkness. He knows all about us. He knows the end/beginning.
He knows our frame and remembers that we are but dust - compare that for going into battle against a mighty lion!

[iv] He was from Kabzeel = "God gathers" and when we remember that Kabzeel which was a remote city in Judah, then God truly gathers His servants from here, there and yonder to do His will
There are no backwaters in God's universe: (Psalm 124:1)
Significant Benaiah was from Judah
First mention/lion is Genesis 49:9
Judah is a lion's whelp: from the prey, my son, thou art gone up:
 he stooped down, he couched as a lion, and as an old lion; who shall rouse him up?
 In many ways, he was well matched for this worst possible foe
His background, coupled with his faith/God, enabled him to face the great lion.

D/ The devil is likened to a roaring, hungry lion (1 Peter 5:8)
You/I especially as believers must face him
He is brutal/strong/vicious/wily and a killer
No alternative to the battle
Take heart! Here is one who took on the great lion and won!

Just as others have done before him
Samson conquered the young lion (Judges 14:5-6)
 David did so (1 Samuel 17:34-36)
When Paul fought with wild beasts at Ephesus, we might ask if they were literal? Again: Did they include lions?
Whatever! Passage teaches us: No foe is invincible if we fight in the strength of our King.

2) THE WORST POSSIBLE PLACE:
In a pit

A/ Not told how both man/beast came to share this one abode at the same time. "Accidental" meeting?
Was it indeed a deliberate meeting?
Sometimes Christians take on things which they know will bring upon them the wrath/hell:
Sometimes when you simply seek/evangelise
Certainly when you raise voice/protest…expect Satanic fight back

B/ Hebrew word for pit also translated as: dungeon/well/cistern
Has been suggested: a cave or even a hollow place i.e. a valley.
 I prefer the idea of the closed up pit with little room to move
And very little room to escape.

C/ Sometimes, we find ourselves in such a pit experience and the more horrific this scene is...then the more comfort it has for us

[i] Unsaved sinners are often shut up/Devil in a very narrow pit
Those determined to hold unto their sins will perish in this pit
Those who are determined to flee their sins will overcome the lion and survive the pit.
What a great struggle perhaps
Times it will look as if the lion/winning but grace is always triumphant for those for whom Christ died
Will be to the death for the lion

[ii] For those in one/many trials of life
We have all been there at one/time or the other
Felt closed in to a cruel foe and we knew fear/depression etc.,
But we always knew victory in the end

[iii] Death's dark vale? Sometimes a great struggle.
Some saints die with absolute ease - others fight there their last/greatest battle against Satan. Cp Pilgrim's Progress
Victory for every Christian/death. We can all say: 1 Cor 15:55  
O death where is thy sting? O grave where is thy victory?
When you pass through death's valley and it cannot stop you from entering into God's presence
 (indeed, it assists you) then death itself has been defeated. Lion receives the fatal wound.

3) THE WORST POSSIBLE TIME:
In a time of snow
 
A/ Likely that the lion was hungry at such a time and therefore the more dangerous/vicious.
Gill again records that lions are said to have their greatest strength in cold weather

B/ Benaiah's hands/feet might well have been benumbed with the severe cold- it was time/snow.
Sure...there were more genial conditions/these

C/ Often the devil does attack when you at your weakest and he most stronger/fierce.
 Do not despair! Victory can still be yours.

D/ Would be amiss in closing to fail/observe the great type:
Benaiah pictures Christ - the Greatest/Judah's sons
 He ascended alone into the pit and fought the lion
They gaped upon me with their mouths, as a ravening and a roaring lion…
Save me from the lion's mouth: for thou hast heard me from the horns of the unicorns. (Psalm 22:13/21)
And He won…destroying the destroyer whether we view it as sin/death/hell (All combined!)
and giving us victory also if we face them in His name, as Benaiah evidently did.