I just found from 2 authentic resources that witr are not compulsary(farz).. and are not part of Isha or any farz namaz.. so if you just pray four farz of Isha, your prayer will be complete..
Witr are to be prayed in tahajud.. or as in, at anytime between Isha & Fajr.. this is how our beloved Prophet Hazrat Muhammad (S.A.W) used to do..
but there are two types of raka’at.. Farz and Sunnah..
Farz is something that is compulsory, one dont offer them, they’ll be accountable for this sin..
Sunnat is something that have the highest ranks in ibadat other than Farz, but if one dont offer them, there is no punishment or accountancy for it.. no matter what they are called, witr, sunnat-e-muaqadah, sunnat-e-ghair-muaqadah, nawafil, etc..
and the point is, Witr are for Tahajud.. but people offer it with Isha coz they are too lazy/dont want to bother, to get up and offer it in the deep night.. also, if a person wakes up before Fajar then it’s wajib on him/her to offer these Witr..
You may want to provide reference as to where you got this.
Because:
It starts when a person has prayed ‘Isha’, even if it is joined to Maghrib at the time of Maghrib, and lasts until dawn begins, because the Prophet (peace and blessings of Allaah be upon him) said: “Allaah has prescribed for you a prayer (by which He may increase your reward), which is Witr; Allaah has enjoined it for you during the time between ‘Isha’ prayer until dawn begins.” Narrated by al-Tirmidhi, 425; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
Once dawn begins, the time for Witr is over, based on the words of the Prophet (peace and blessings of Allaah be upon him): “Pray Witr before morning comes.” Narrated by Muslim, 754.
Muslim also narrated from Ibn ‘Umar (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Hasten to pray witr before dawn.”
And Muslim narrated (752) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Witr is one rak’ah at the end of the night.”
Al-Tirmidhi narrated (469) from Ibn ‘Umar (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “When dawn comes, all the night prayers and Witr are over, so pray Witr before dawn comes.” Classed as saheeh by al-Albaani in * Saheeh al-Tirmidhi.*
Al-Bukhaari (472) and Muslim (749) narrated that the Prophet (peace and blessings of Allaah be upon him) said: “The night prayers are two (rak’ahs) by two, then when you think that morning (dawn) is about to begin, pray one (rak’ah) and it will make what you have prayed Witr (odd-numbered).”
Shaykh Ibn ‘Uthaymeen said:
This indicates that the time for Witr ends when the dawn comes, because it is a prayer with which the night prayers are concluded, so it cannot be done after the night has ended.
Allow me rephrase my earlier point quoted by you. It is in situation where a person intend to offer Witr at late night but overslept, he/she may offer it even after sun-rise. In another hadith word “forgets” also included. Please see the below hadiths.
In Book: The Book 3 Hadith 14 on Al-Witr - أَبْوَابُ الْوِتْرِ, graded ‘Sahih’ by Darussalam, referenced by Jami’ At-Timidhi: "Abu Sa’eed Al-Khudri narrated that : Allah’s Messenger said: “Whoever sleeps past Al-Witr or forgets it, then let him pray it when he remembers it or when he awakens.”
Also in same Book 3 vide Hadith No. 15 on Al-Witr: "Zaid bin Aslam narrated from his father that: the Prophet said: “Whoever sleeps past his Al-Witr then let him pray it in the morning.”