Charles H. Spurgeon on Psalms 106:14

In the wilderness. There, where they had bread enough and to spare, yet nothing would serve them but they must have flesh to eat. They were now purely at God's finding; so that this was a reflection upon the wisdom and goodness of their Creator. They were now, in all probability, within a step of Canaan, yet had not patience to stay for dainties till they came thither. They had flocks and herds of their own, but they will not kill them; God must give them flesh as he gave them bread, or they will never give him credit or their good word: they did not only wish for flesh, "but" they "lusted exceedingly" after it. A desire even of lawful things, when it is inordinate and violent, becomes sinful; and therefore this is called "lusting after evil things", (1Co 10:6), though the quails as God's gift, were good things, and were so spoken of, Ps 105:40. Yet this was not all, "they tempted God in the desert", where they had had such experience of his goodness and power, and questioned whether he could and would gratify them therein. See Ps 78:19-20. Matthew Henry.