Hadiths 7.93 and 7.94

7.93:
Narrated `Aisha:
That she borrowed a necklace from Asma' and then it got lost.
So Allah's Apostle sent some people from his companions in
search of it. In the meantime the stated time for the prayer
became due and they offered their prayer without ablution.
When they came to the Prophet, they complained about it to
him, so the Verse regarding Tayammum was revealed . Usaid bin
Hudair said, "(O `Aisha!) may Allah bless you with a good
reward, for by Allah, never did a difficulty happen in
connection with you, but Allah made an escape from it for you,
and brought Allah's Blessings for the Muslims."

7.94:
Narrated Ibn `Abbas: The Prophet said, "If anyone of you, when
having sexual intercourse with his wife, says: Bismillah,
Allahumma jannibni−Sh−Shaitan wa jannib−ish−Shaitan ma
razaqtana, and if it is destined that they should have a
child, then Satan will never be able to harm him."