The Prophet (peace and blessings be upon him) said:
"There are three things in which seriousness is serious and jest is also counted as serious: marriage, divorce and taking back (a divorced wife)."
Hadith Referenceصحیح الجامع الصغیر / حرف الثاء / 3027
Hadith Gradingالألبانی:حسن
Hadith Takhrij[د ت هـ] عن أبي هريرة. المشكاة ٣٢٨٤، الإرواء ١٨٢٦، ٢٠٦١.