Are not two sparrows ... - He encourages them not to fear by two striking considerations: first, that God takes care of sparrows, the smallest and least valuable of birds; and, secondly, by the fact that God numbers even the hairs of the head. The argument is, that if He takes care of birds of the least value, if He regards so small a thing as the hair of the head, and numbers it, He will certainly protect and provide for you. You need not, therefore, fear what man can do to you.
Sparrows - The sparrows are well-known birds in Syria. They are small; they are found in great numbers; they are tame, intrusive, and nestle everywhere. “They are extremely pertinacious in asserting their right of possession, and have not the least reverence for any place or thing. David alludes to these characteristics of the sparrow in Psalms 84:1-12, when he complains that they had appropriated even the altars of God for their nests. Concerning himself, he says, I watch, and am as a sparrow upon the housetop, Psalms 102:7. When one of them has lost its mate - a matter of everyday occurrence - he will sit on the housetop alone, and lament by the hour his sad bereavement. These birds are snared and caught in great numbers, but, as they are small, and not much relished for food, five sparrows may still be sold for two farthings; and when we see their countless numbers, and the eagerness with which they are destroyed as a worthless nuisance, we can better appreciate the assurance that our heavenly Father, who takes care of them, so that not one can fall to the ground without his notice, will surely take care of us, who are of more value than many sparrows.” - “The Land and the Book” (Thomson), vol. i. pp. 52, 53.
Farthing - See the notes at Matthew 5:26.
Without your Father - That is, God, your Father, guides and directs its fall. It falls only with His permission, and where He chooses.
The very hairs of your head are all numbered - That is, each one has exercised the care and attention of God.
He has fixed the number; and, though of small importance, yet he does not think it beneath him to determine how few or how many they shall be. He will therefore take care of you.