The Prophet (saws) said: The best number of companions is four, the best number in expeditions four hundred, and the best number in armies four thousand; and twelve thousand will not be overcome through smallness of numbers.

Abu Dawud said: What is correct is that this tradition is mursal (i.e. the link of the Companion is missing).

A hadith like this has been narrated on the authority of Humaid with the same chain of transmitters.

Allah's Apostle used to keep silent between the Takbir and the recitation of Qur'an and that interval of silence used to be a short one. I said to the Prophet "May my parents be sacrificed for you! What do you say in the pause between Takbir and recitation?" The Prophet said, "I say, 'Allahumma, baa`id baini wa baina khatayaya kama baa`adta baina l-mashriqi wa l-maghrib. Allahumma, naqqini min khatayaya kama yunaqqa th-thawbu l-abyadu mina d-danas. Allahumma, ighsil khatayaya bi l-maa'i wa th-thalji wa l-barad (O Allah! Set me apart from my sins (faults) as the East and West are set apart from each other and clean me from sins as a white garment is cleaned of dirt (after thorough washing). O Allah! Wash off my sins with water, snow and hail.)"

'A'isha, the wife of the Apostle (may peace be upon him), said that the Messenger of Allah (may peace be upon him) said the afternoon prayer (at the time) when the sun shone in her apartment and its shadow did not extend beyond her apartment.

The Prophet used to invoke Allah with the following invocation: 'Rabbi-ghfir-li Khati 'ati wa jahli wa israfi fi `Amri kullihi, wa ma anta a'lamu bihi minni. Allahumma ighfirli khatayaya wa 'amdi, wa jahli wa jiddi, wa kullu dhalika'indi. Allahumma ighrifli ma qaddamtu wa ma akhartu wa ma asrartu wa ma a'lantu. Anta-l-muqaddimu wa anta-l-mu'akh-khiru, wa anta 'ala kulli shai'in qadir.'

When the Prophet got up at night to offer the night prayer, he used to say: "Allahumma laka l-hamdu; Anta nuras-samawati wal ardi wa man fihinna. wa laka l-hamdu; Anta qaiyim as-samawati wal ardi wa man flhinna. Wa lakaI-hamdu; Anta-l-,haqqun, wa wa'daka haqqun, wa qauluka haqqun, wa liqauka haqqun, wal-jannatu haqqun, wannaru haqqun, was-sa atu haqqun, wan-nabiyyuna huqqun, Mahammadun haqqun, Allahumma laka aslamtu, wa Alaika tawakkaltu, wa bika amantu, wa ilaika anabtu, wa bika Khasamtu, wa ilaika hakamtu, faghfirli ma qaddamtu wa ma akh-khartu, wa ma asrartu, wa ma a'lantu. Anta al-muqaddimu, wa anta al-mu-'akhkhiru. La ilaha il-la anta (or La ilaha ghairuka)"

The Prophet used to invoke Allah, saying, "Allahumma ighfirli khati'ati wa jahli wa israfi fi `Amri, wa ma anta a-'lamu bihi minni. Allahumma ighfirli hazali wa jiddi wa khata'i wa amdi, wa kullu dhalika 'indi."

Another chain reports a similar hadith.

The Prophet used to teach us the Istikhara for each and every matter as he used to teach us the Suras from the Holy Qur'an. (He used to say), "If anyone of you intends to do something, he should offer a two-rak`at prayer other than the obligatory prayer, and then say: 'Allahumma inni astakhiruka bi'ilmika, wa astaqdiruka biqudratika, wa as'aluka min fadlika-l-'azim, fa innaka taqdiru wala aqdiru, wa ta'lamu wala a'lamu, wa anta'allamu-l-ghuyub. Allahumma in kunta ta'lamu anna hadha-lamra khairun li fi dini wa ma'ashi wa 'aqibati `Amri (or said, fi 'ajili `Amri wa ajilihi) fa-qdurhu li, Wa in kunta ta'lamu anna ha-dha-l-amra sharrun li fi dini wa ma'ashi wa 'aqibati `Amri (or said, fi ajili `Amri wa ajilihi) fasrifhu 'anni was-rifni 'anhu wa aqdur li alkhaira haithu kana, thumma Raddani bihi," Then he should mention his matter (need).

The people said, "O Allah's Apostle ! How may we send Salat on you?" He said, "Say: Allahumma Salli 'ala- Muhammadin wa azwajihi wa dhurriyyatihi kama sal-laita 'ala `Ali Ibrahim; wa barik 'ala Muhammadin wa azwajihi wa dhurriyyatihi kamabarakta 'ala `Ali Ibrahim innaka hamidun majid."

That the Prophet advised a man, saying, "If you intend to lie down (i.e. go to bed), say, 'Allahumma aslamtu nafsi ilaika wa fauwadtu `Amri ilaika, wa wajjahtu wajhi ilaika wa alja'tu zahri ilaika, reghbatan wa rahbatan ilaika. La malja'a wa la manja minka illa ilaika. Amantu bikitabikal-ladhi anzalta; wa nabiyyikalladhi arsalta.' And if you should die then (after reciting this before going to bed) you will die on the religion of Islam"