Deuteronomy 10:17
15 However, only to your ancestors did he show his loving favor, and he chose you, their descendants, from all peoples—as is apparent today. 16 Therefore, circumcise your hearts and stop being so stubborn! 17 For the Lord your God is God of gods and Lord of lords, the great, mighty, and awesome God who is unbiased and takes no bribe, 18 who justly treats the orphan and widow, and who loves resident foreigners, giving them food and clothing. 19 So you must love the resident foreigner because you were foreigners in the land of Egypt.
Ephesians 6:9
7 Obey with enthusiasm, as though serving the Lord and not people, 8 because you know that each person, whether slave or free, if he does something good, this will be rewarded by the Lord. 9 Masters, treat your slaves the same way, giving up the use of threats, because you know that both you and they have the same master in heaven, and there is no favoritism with him. 10 Finally, be strengthened in the Lord and in the strength of his power. 11 Clothe yourselves with the full armor of God, so that you will be able to stand against the schemes of the devil.
Notes and References
"... First, the writer reminds masters that “both their and your Master is in heaven,” whereas Colossians 4:1 simply has “you also have a Master in heaven.” Then he adds “and there is no partiality with him.” This thought has now been employed in connection with both groups in Ephesians (compare the equivalent “whether slave or free” in verse 8) in contrast to Colossians, where it is only used in regard to slaves. Mitton notes the appropriateness of the emphasis on impartiality being used in the address to masters rather than to slaves, since the higher up in social status people feel themselves to be, the more likely they are to expect to be accorded special consideration. The noun προσωπολημψία, “partiality” (compare Colossians 3:25; Romans 2:11), comes from the Hebraistic verbal expression πρόσωπον λαμβάνειν, “to show partiality, to judge purely at face value or on the basis of external factors” (compare Leviticus 19:15; Deuteronomy 10:17; Sirach 4:22, 27; 1 Esdras 4:39; Luke 20:21; Galatians 2:6; Barnabas 19:4; Didache 4:3). In the Old Testament and Jewish writings, impartiality in judgment is attributed to God (compare especially Sirach 35:11–13; Jubilees 5:15–19; Psalms of Solomon 2:18; compare also Romans 2:11; 1 Peter 1:17), but here and in Colossians this is transferred to Christ as Lord ..."
Lincoln, Andrew T. Word Biblical Commentary: Ephesians (p. 1206) Zondervan, 2017