Can you please help me find this ayah in which surah, dua, hadith and it's meaning in English.

Ridham bi kadha-ihi wa tasliman li amrih

It is not Aayat but it was sentence said by Imam Husain as after the shahadat of Hazrat Ali Asghar while he was carrying the body towards tent his tent he said seven times Inna lillah e wa inna elaihe rajeoon
Ridhan beqadaehi wa tasleeman leamreh
Imam Zamana as in his ghaibate sughra when he sent his condolences to his second representative Mohammad bin Usman on death of his father (first representative Usman bin Saeed) he wrote the above sentence .
It means “I’m happy with your decision and submitted myself to your command."