C. F. Keil and Franz Delitzsch on Ecclesiastes 3:7

Ecc 3:7 7 a. “To rend has its time, and to sew has its time.” When evil tidings come, when the tidings of death come, then is the time for rending the garments (2Sa 13:31), whether as a spontaneous outbreak of sorrow, or merely as a traditionary custom. - The tempest of the affections, however, passes by, and that which was torn is again sewed together.

Perhaps it is the recollection of great calamities which leads to the following contrasts: - 7 b. “To keep silence has its time, and to speak has its time.” Severe strokes of adversity turn the mind in quietness back upon itself; and the demeanour most befitting such adversity is silent resignation (cf. 2Ki 2:3, 2Ki 2:5). This mediation of the thought is so much the more probable, as in all these contrasts it is not so much the spontaneity of man that comes into view, as the pre-determination and providence of God.

The following contrasts proceed on the view that God has placed us in relations in which it is permitted to us to love, or in which our hatred is stirred up: -