Jamieson, Fausset and Brown on Matthew 5:45

45. That ye may be the children--sons.

of your Father which is in heaven--The meaning is, "that ye may show yourselves to be such by resembling Him" (compare Mt 5:9; Ep 5:1).

for he maketh his sun--"your Father's sun." Well might Bengel exclaim, "Magnificent appellation!"

to rise on the evil and on the good, and sendeth rain on the just and on the unjust--rather, (without the article) "on evil and good, and on just and unjust." When we find God's own procedure held up for imitation in the law, and much more in the prophets (Le 19:2; 20:26; and compare 1Pe 1:15, 16), we may see that the principle of this surprising verse was nothing new: but the form of it certainly is that of One who spake as never man spake.