John Trapp on Psalms 44:2

Verſ. 2. How thou didſt drive out the Heathen] i.e. The Canaanites. Theſe, God the great Proprietary of all ſupplanted, after that they had for a long time grown there as trees, and abounded with all kind of ſenſual delights till they had filled the Land from one end to the other with their uncleanneſſe, Ezra 9.11.

How thou didſt afflict (or break in peeces) the people and caſt them out] Or, cauſe them (the Iſraelites) to ſpread and propagate. (So Mollerus readeth it) as the Vine ſendeth out her branches.