King James Version (KJV)
With the merciful thou wilt shew thyself merciful, {and} with the upright man thou wilt shew thyself upright.
Modern English
With the merciful you will show yourself merciful. With the perfect man you will show yourself perfect.
Hebrew
עִם־חָסִ֖יד תִּתְחַסָּ֑ד עִם־גִּבּ֥וֹר תָּמִ֖ים תִּתַּמָּֽם׃
ʿim-ḥasiyd titḥasad ʿim-gibvor tamiym titamam