Virtues
Ibn 'Abbas, may Allah be pleased with them, narrated:Allah's Messenger (may peace be upon him) transmitted it from the Blessed and Great Lord: Verily Allah recorded the good and the evil and then made it clear that he who intended good but did not do it, Allah recorded one complete virtue in his favor, but if he intended it and also did it, the Glorious and Great Allah recorded ten to seven hundred virtues and even more to his credit. But if he intended evil but did not commit it, Allah wrote down one full virtue in his favor. If he intended that and also committed it, Allah made an entry of one evil against him.
Hadith number in Sahih Muslim [Arabic only]: 187

Three are the persons with whom Allah would neither speak on the Day of Resurrection

Abu Hurairah, may Allah be pleased with him, reported:Allah's Messenger (may peace be upon him) said: Three are the persons with whom Allah would neither speak on the Day of Resurrection, nor would He look towards them, nor would purify them (from sins), and there would be a tormenting chastisement for them: a person who in the waterless desert has more water (than his need) and refuses to give it to the traveler, a person who sold a commodity to another person in the afternoon and took an oath of Allah that he had bought it at such and such price and he (the buyer) accepted it to be true though it was not, and a person who pledged allegiance to the Imam only for the sake of the world (material gains). And if the Imam bestowed on him (something) out of that (worldly riches) he stood by his allegiance; and if he did not give him, he did not fulfill the allegiance.
Hadith number in Sahih Muslim [Arabic only]: 157



Which sin is the gravest in Allah's sight?
'Abdullah bin Mas'ud, may Allah be pleased with him, reported:
I asked Allah's Messenger (may peace be upon him): Which sin is the gravest in Allah's sight? He (the Holy Prophet) replied: That you associate a partner with Allah, while it is He Who has created you. He (the reporter) said: I told him (the Holy Prophet): Verily it is indeed grave. He (the reporter) said: I asked him what the next (gravest sin) was. He (the Holy Prophet) replied: That you kill your child out of fear that he will join you in food. He (the reporter) said: I asked (him) what the next (gravest sin) was. He (the Holy Prophet) observed: Then (the next gravest sin) is that you commit adultery with the wife of your neighbor.
Hadith number in Sahih Muslim [Arabic only]: 124