جَزَاكَ اللَّهُ خَيْرَاً
"May Allah grant you (in return) a good reward".
(Mishkat)
When you love someone make it known by saying
أَحَبَّكَ الَّذِي أَحْبَبْتَنِي لَهُ
"May Allah love you for whom you have loved me".
(Abu Dawood)
When seeing a muslim in new clothes
تُبْلِي وَيُخْلِفُ اللَّهُ
"May Allah prolong your life so that this clothing become old and may Allah give you other clothing after this".
(Hisnul Hasin from Abu Dawood)
When wearing new clothes
اللَّهُمَّ لَكَ الْحَمْدُ كَمَا كَسَوْتَنِيهِ أَسْأَلُكَ خَيْرَهُ وَخَيْرَ مَا صُنِعَ لَهُ وَأَعُوذُ مِنْ شَرِّهِ وَشَرِّ مَا صُنِعَ لَهُ
"O Allah, all praise is to You, just as You have dressed me, I seek Your blessings of it and the blessings of what it is made of and I seek protection and Your refuge from all evil and the evil of that which it is made of".
(Mishkat)
When one sees a muslim laughing
أَضْحَكَ اللَّهُ سِنَّكَ
"Allah keep you laughing".
(Mishkat, Bukhari)
When someone is in a difficulty
الْحَمْدُ لِلَّهِ الَّذِي عَافَانِي مِمَّا ابْتَلَاكَ بِهِ وَفَضَّلَنِي عَلَى كَثِيرٍ مِمَّنْ خَلَقَ تَفْضِيلَاً
"All praise belongs to Allah who has saved me from such a condition which is afflicted on you and favoured me over many creations". The virtues of this dua is that the reciter will be saved from the difficulties he has seen".
(Mishkat)
When hearing someone sneeze
يَرْحَمُكَ اللَّهُِ
"May Allah have mercy on you".
(Mishkat, Bukhari)
Dua when sneezing
الْحَمْدُ لِلَّهِ
"Thanks and All praise is for Allah".
When biding farewell to someone going off on a journey, recite
أَسْتَوْدِعُ اللَّهَ دِينَكَ وَأَمَانَتَكَ وَخَوَاتِيمَ عَمَلِكَ
"(I make) Allah responsible for your deen, your trustworthiness and for the results of your actions". If there is a darkness with the heavy wind, recite Surah Falaq and Surah Naas.
(Tirmidhi)
When sighting the new moon
ِأَعُوذُ بِاللَّهِ مِنْ شَرِّ هَذَا
"I seek refuge in Allah from this (its) evil"
اللَّهُمَّ أَهِلَّهُ عَلَيْنَا بِالْيُمْنِ وَالْإِيمَانِ وَالسَّلَامَةِ وَالْإِسْلَامِ وَالتَّوْفِيقِ لِمَا تُحِبُّ وَتَرْضَى رَبِّي وَرَبُّكَ اللَّهُ
"O Allah, let this moon (month) pass over us with blessings, Iman, safety, and in the belief of Islam. Grant us the ability to act on the actions that You love and Pleases You. (O moon) My Lord and Your Lord is Allah."
(Hisnul Hasin from Ibn Habban)
At the time of heavy winds
اللَّهُمَّ اجْعَلْهَا رَحْمَةً وَلَا تَجْعَلْهَا عَذَابَاً اللَّهُمَّ اجْعَلْهَا رِيَاحَاً وَلَا تَجْعَلْهَا رِيحَاً
"O Allah, let it be a mercy and not a punishment. O Allah make it a beneficial and not a destructive wind". If there is a darkness with the heavy wind, recite Surah Falaq and Surah Naas.
(Mishkat)
When rain exceeds the limits
اللَّهُمَّ حَوَالَيْنَا وَلَا عَلَيْنَا اللَّهُمَّ عَلَى الْأَكَامِ وَالْأَجَامِ وَالظِّرَابِ وَالْأَدْوِيَةِ وَمَنَابِةِ الشَّجَرِ
"O Allah, let it rain around us and not on us. O Allah, let it rain on the peaks and mountains and the rivers and at the forests."
(Tirmidhi, Bukhari, Muslim)