C. F. Keil and Franz Delitzsch on Daniel 1:9

Dan 1:9 לחסד נתן, to procure favour for any one, cf. 1Ki 8:30; Psa 106:46; Neh 1:11. The statement that God gave Daniel favour with the chief chamberlain, refers to the fact that he did not reject the request at once, as one not to be complied with, or as punishable, but, esteeming the religious conviction out of which it sprang, pointed only to the danger into which a disregard of the king’s command would bring him, thus revealing the inclination of his heart to grant the request. This willingness of the prince of the eunuchs was the effect of divine grace.