Hadith verification

Q: I just wanted to know the actual hadith and the reference. They were both in regards to the ummah being forgiven.

1st Hadith more or less - our Beloved Master Sallallahu Alaihi Wasallam was travelling and near the outskirts of Madina made dua 3 times and fell into sujood 3 times - was informed each time 1/3 of the ummah was forgiven each time.

2nd Hadith, the Beloved Sallallahu Alaihi Wasallam was told He would be very pleased with how Allah Ta'ala will treat the ummah on that day.

Replying to salaam correctly

Q: A known person to me sometimes greet me as Assamualekum without la in it, clearly. Sometimes I reply to him in forgetfulness Walekum assalam, instead of Walekum. Then I realize that, and don't know what to read as a counteract to that. Could you please tell me what to do at that times?