Hadithcore
Hadith #2113390

al-Harith bin Abu Usamah reported from the Hadith of 'Ubadah bin as-Samit [RA) - tracing it to the Prophet (ﷺ):

"It is not permissible to play in three things: divorce, marriage and emancipation. Therefore, whoever pronounce (either of) them, they certainly become binding." [Its chain of narrators is Da'if (weak)].

وَلِلْحَارِثِ اِبْنِ أَبِي أُسَامَةَ : مِنْ حَدِيثِ عُبَادَةَ بْنِ اَلصَّامِتِ رَفَعَهُ : { لَا يَجُوزُ اَللَّعِبُ فِي ثَلَاثٍ : اَلطَّلَاقُ , وَالنِّكَاحُ , وَالْعِتَاقُ , فَمَنْ قَالَهُنَّ فَقَدَ وَجَبْنَ } وَسَنَدُهُ ضَعِيفٌ [1]‏ .‏

References2 variants
Sunnah.com reference
Book 8, Hadith 132
Arabic/English book reference
Book 8, Hadith 1088