They cried, but there was none to save them: even unto the Lord, but he answered them not. It seems strange, at first sight, that the heathen enemies of David should "cry unto the Lord," i.e. to Jehovah; and hence some have been driven to suppose that a victory over domestic enemies is here interpolated into the series of foreign victories.
But it seems better to explain, with Hengstenberg and the 'Speaker's Commentary,' that the heathen did sometimes, as a last resort, pray to a foreign god, whom they seemed to find by experience to be more powerful than their own (see Jonah 1:14).
Jehovah was known by name, as the God of the Israelites, to the surrounding nations. Mesha mentions him upon the Moabite Stone; and Sennacherib declared, by the mouth of Rabshakeh, "Am I come up without the Lord against this place to destroy it?
The Lord (Jehovah) said to me, Go up against this land, and destroy it" (2 Kings 18:25).