Given below are some sayings of Prophet Muhammad (s.a.a.w.) about daughters:
"The person who is put to a test because of the birth of the daughters and then he treats them generously, they will become a means of rescue for him from Hell." (Bukhari, Muslim).
"The one who brought up two girls till they attained their maturity, will appear along with me on the Resurrection Day ... Saying this the Holy Prophet jointed and raised his fingers. (Muslim).
"The one who brought up three daughters, or sisters, taught then good manners and treated them with kindness until they became self-sufficient. AIlah will make Paradise obligatory for him. A man asked: what about two, O Messenger of Allah? The Holy Prophet replied: the same for two." Ibn `Abbas, the reporter of the Hadith, says: "Had the people at that time asked in respect of one daughter, the Holy Prophet would have also given the same reply about her. " (Sharh as-Sunnh).
"The one who has three daughters born to him, and he is patient over them, and clothes them well according to his means, they will become a means of rescue for him from Hell. " (Bukhari, Al-Adab al-Mufrad, Ibn Majah).
"The Muslim who has two daughters and he looks after them well, they will lead him to Paradise." (Bukhari: Al-Adab al-Mufrad).
The Holy Prophet said to Suraqah bin Ju'sham: "Should I tell you what is the greatest charity (or said: one of the greatest charities)? He said: Kindly do tell, O Messenger of Allah. The Holy Prophet said: Your daughter who (after being divorced or widowed) returns to you and should have no other bread-winner." (Ibn Majah, Bukhari Al-Adab al-Mufrad).
These are the teachings which completely changed the viewpoint of the people about girls not only in Arabia but among all the nations of the world, which later became blessed with Islam.