Is it permissible to say: "Praise be to Allah always and forever?"

It is permissible to say "Alhamdulillah da'iman wa abadan" (Praise be to Allah always and ever), because it is among the best praises of Allah, and the wordings of praise are not restricted (tawqifiyyah). Scholars have used the hadith of Rifaa ibn Rafi', who introduced an unaccustomed dhikr (remembrance) in prayer, and the Prophet (peace be upon him) approved it, as evidence for the permissibility of introducing unaccustomed dhikr, as long as it does not contradict what is accustomed. Al-Dhahabi mentioned the phrase "wal-hamdulillah da'iman abadan" (and praise be to Allah always and ever) in "Al-Kaba'ir" (Major Sins).