Pray for those who have passed away; Worship only one god; Participate in funeral prayer over a deceased Muslim; Ask others to join you in prayer too; Believe your prayers will be accepted by God .

This hadith teaches us the importance of praying for the deceased. It is narrated by Ibn 'Abbas that the Prophet Muhammad said that if forty people who do not associate anything with Allah in worship, pray for a deceased Muslim, then Allah will accept their intercession. This means that when we pray for someone who has passed away, it can help them in the afterlife and bring them closer to God's mercy and forgiveness. The number forty is significant because it is seen as a large enough group to make an impact on God's decision-making process. Furthermore, this hadith also emphasizes the importance of worshipping only one God and not associating any other gods or idols with Him. By doing so we can ensure our prayers are accepted by Him and our deeds are rewarded accordingly.