The Command to have Taqwa and to prepare for the Day of Resurrection
Imam Ahmad recorded that Al-Mundhir bin Jarir narrated that his father said,
"While we were in the company of the Messenger of Allah in the early hours of the morning, some people came there who were barefooted, naked, wearing striped woolen clothes, or cloaks, with their swords hung (around their necks). Most of them, nay, all of them, belonged to the tribe of Mudar. The color of the face of the Messenger of Allah underwent a change when he saw them in poverty. He then entered (his house) and came out and commanded Bilal to pronounce Adhan. Bilal pronounced Adhan and Iqamah, and the Prophet led the prayer. He then addressed them, first reciting,
يَـأَيُّهَا النَّاسُ اتَّقُواْ رَبَّكُمُ الَّذِى خَلَقَكُمْ مِّن نَّفْسٍ وَحِدَةٍ
O mankind! Have Taqwa of your Lord, Who created you from a single person... (4;1), until the end of the Ayah.
Then he recited the Ayah that is in Surah Al-Hashr;
وَلْتَنظُرْ نَفْسٌ مَّا قَدَّمَتْ لِغَد
and let every person look to what he has sent forth for tomorrow,"
He then said,
"A man donated his Dinar, his Dirham, from his clothes, from his Sa` of wheat, from his Sa` of dates" -- until he said -- "even if it was half a date."
Then a person among the Ansar came there with a moneybag, which his hands could scarcely lift; in fact, his hands could not lift it. Then the people followed continuously, until I saw two heaps of eatables and clothes. I saw the face of the Messenger radiate with pleasure, like gold. The Messenger of Allah said,
مَنْ سَنَّ فِي الاِْسْلَمِ سُنَّةً حَسَنَةً فَلَهُ أَجْرُهَا وَأَجْرُ مَنْ عَمِلَ بِهَا بَعْدَهُ مِنْ غَيْرِ أَنْ يُنْقَصَ مِنْ أُجُورِهِمْ شَيْءٌ
وَمَنْ سَنَّ فِي الاِْسْلَمِ سُنَّةً سَيِّيَةً كَانَ عَلَيْهِ وِزْرُهَا وَوِزْرُ مَنْ عَمِلَ بِهَا مِنْ غَيْرِ أَنْ يُنْقَصَ مِنْ أَوْزَارِهِمْ شَيْء
He who sets a good example in Islam, there is a reward for him for this (act of goodness) and reward of that also who acted according to it subsequently, without any deduction from their rewards.
Whoever sets in Islam an evil example, there is upon him the burden of that evil and the burden of him also who acted upon it subsequently, without any deduction from their burden."
Muslim recorded this Hadith via the chain of Shu`bah.
Therefore, Allah's statement,
يَا أَيُّهَا الَّذِينَ امَنُوا اتَّقُوا اللَّهَ
O you who believe! Have Taqwa of Allah,
ordains the Taqwa of Allah which pertains to obeying what He ordered and staying away from what He forbade.
Allah said,
وَلْتَنظُرْ نَفْسٌ مَّا قَدَّمَتْ لِغَدٍ
and let every person look to what he has sent forth for tomorrow,
meaning, hold yourselves accountable before you are recompensed, and contemplate what you have kept for yourselves of good deeds for the Day of your return and being paraded before your Lord,
وَاتَّقُوا اللَّهَ
Have Taqwa of Allah,
again ordering Taqwa,
إِنَّ اللَّهَ خَبِيرٌ بِمَا تَعْمَلُونَ
Verily, Allah is All-Aware of what you do.
Allah asserts that surely, He knows all of your deeds -- O mankind -- and actions. Nothing that pertains to you ever escapes His observation, nor any matter of yours, whether major or minor, is ever beyond His knowledge