In Matthew 6:25-26 we have an argument against giving place to the cares of this world, on the ground that they are unworthy of an immortal being like man; and also an illustration pointedly leading to the exercise of faith.
I. The question before the Lord was not whether we should be as idle as the birds, but only whether we should, like them, cast off care and trust our heavenly Father. Toil is man's lot. He must sow and reap. We cannot expect the daily manna unless we go and gather it. The argument is not against labour, but against worldly care; and this is the purport of it: God cares for the little birds; He provides their food in due season; and they, instead of burdensome anxiety, in their unconscious gratitude are ever hymning His praise. Now this God is your Father; ye are the children of the Highest; and if He provides for the very birds, how much more will a Father's love and watchfulness care for each of you. Only trust Him, therefore, and all shall be well.
II. The Lord exhorts us to seek first the kingdom of God and His righteousness. This is the pith and kernel of the whole matter. What He means is, that they are not to set their hearts on the kingdom, the possessions, of this world its riches and honours, and pampering indulgences and vain displays; neither are they to vex their hearts with cares concerning these, as the Gentiles do, sinking thereby into a like degradation with them, but they are to make it their foremost object to obtain spiritual treasures meekness, temperance, patience, faith, love, and all things just and true and honest and pure and lovely, which are the true riches and real honours of man, the only dignities acknowledged in the kingdom of God. Now the way to obtain these is through faith in God and His Christ. Their great effort, therefore, should be to believe that God reigns, and to trust Him with a most loyal and unswerving devotion. This is obviously what is here meant by seeking the kingdom of God. The righteousness of God here meant is the righteousness of His government His all-holy and wise administration, which we are to cherish with a steadfast faith.
W. C. Smith, The Sermon on the Mount,p. 239.
References: Matthew 6:25-34. J. C. Jones, Studies in St. Matthew,p. 146. Matthew 6:26. Spurgeon, Morning by Morning,p. 26; A. J. Griffith, Christian World Pulpit,vol. xv., p. 140; J. M. Neale, Sermons to Children,p. 204.Matthew 6:26-28. H. J. Wilmot-Buxton, Waterside Mission Sermons,vol. i., No. 16.