Reference for Bava Metzia 221:11

איזה הוא עושק ואיזהו גזל א"ר חסדא (משלי ג, כח) לך ושוב לך ושוב זה הוא עושק יש לך בידי ואיני נותן לך זה הוא גזל

go and come again' — that is 'oppression';<span class="x" onmousemove="('comment',' I.e., continually deferring payment, though intending to pay eventually. ');">¹⁸</span> 'You have indeed a charge upon me, but I will not pay it' — that is 'robbery'. To this R. Shesheth demurred:<span class="x" onmousemove="('comment',' [It is clear from Rashi that what follows is not a citation from a Baraitha, but a piece of R. Shesheth's own Biblical exegesis.] ');">¹⁹</span>

Jastrow