“Or if he ask a fish, will he give him a serpent?”
Matthew 7:10 — Greek Interlinear
Church Fathers on Matthew 7:10
As above He had cited the birds of the air and the lilies of the field, that our hopes may rise from the less to the greater; so also does He in this place, when He says, 'Or what man among you?'
Lest perchance any one considering how great is the difference between God and man, and weighing his own sins should despair of obtaining, and so never take in hand to ask; therefore He proposes a comparison of the relation between father and son; that should we despair because of our sins, we may hope because of God’s fatherly goodness.
There are two things behoveful for one that prays; that he ask earnestly; and that he ask such things as he ought to ask. And those are spiritual things; as Solomon, because he asked such things as were right, received speedily.