Surah An-Nisa' 4:129

ﱢ ﱣ ﱤ ﱥ ﱦ ﱧ ﱨ ﱩ ﱪ ﱫ ﱬ ﱭ ﱮ ﱯ ﱰ ﱱ ﱲ ﱳ ﱴ ﱵ ﱶ ﱷ ﱸ ﱹ

And you will never be able to be equal [in feeling] between wives, even if you should strive [to do so]. So do not incline completely [toward one] and leave another hanging. And if you amend [your affairs] and fear Allah - then indeed, Allah is ever Forgiving and Merciful.