Salim bin 'Abdullah bin 'Umar سالم بن عبد الله بن عمر بن الخطاب · The Book of Marriage

"None of you should propose marriage to a woman when someone else has already proposed to her."

"The Messenger of Allah used to teach his Companions to perform Istikharah in all matters, just as he used to teach them Surahs from the Qur'an. He said: 'If any one of you is deliberating about a decision he has to make, then let him pray two Rak'ahs of non-obligatory prayer, then say: Allahumma inni astakhiruka bi 'ilmika wa astaqdiruka bi qudratika wa as'aluka min fadlika, fa innaka taqdiru wa la aqdir, wa ta'lamu wa la a'lam, wa anta 'allam…

"A bed for a man, a bed for his wife, a third for his guest and the fourth is for the Shaitan."