RASHI
1.
Because so are His ways, to pay a measure for a measure. Kind… sincere… pure, corresponding to the three patriarchs.
עִם־חָסִ֥יד תִּתְחַסָּ֑ד עִם־גְּבַ֥ר תָּ֝מִ֗ים תִּתַּמָּֽם
ʿim–chosiyd tischassod ʿim–ggevar tomiym tittammom
With the merciful, You show Yourself merciful, with a sincere man, You show Yourself sincere.
1.
Because so are His ways, to pay a measure for a measure. Kind… sincere… pure, corresponding to the three patriarchs.