1- لَوْلَا اَنْ اَشُقَّ عَلٰى اُمَّتِيْ لَفَـرَضْتُ عَلَيْہِمُ السِّوَاكَ كَمَا فَـرَضْتُ عَلَيْہِمُ الْوُضُو ْءَ If I had not taken care of the difficulties of my Ummah, I would have made Miswak Fard for them in a way as I have made Wudu Fard for them. (Musnad Ahmad, vol. 1, pp. 459, Hadees 1835)

2- لَوْلَا اَنْ اَشُقَّ عَلٰى اُمَّتِيْ لَاَمَرْتُهُمْ اَنْ يُّـؤََخِّـرُوا الْعِشَاءَ اِلٰى ثُلُثِ اللَّيْلِ اَوْ نِصْفِہٖ, If I had not taken care         of the difficulties of my Ummah, I surely would have ordered to delay ‘Isha Salah to one-third of the night or to midnight. (Sunan-ut-Tirmizi, vol. 1, pp. 214, Hadees 167)

3- وَلَوْلاَ ضَعْفُ الضَّعِيفِ وَسُقْمُ السَّقِيمِ لَاَخَّرْتُ هٰذِهِ الصَّلَاةَ اِلٰى شَطْرِ اللَّيْلِ If I had not taken care of the weakness of the old and the illness of patients, I surely would have delayed this Salah (i.e. ‘Isha Salah) till midnight.

(Abu Dawood, vol. 1, pp. 185, Hadees 422)

Dear Islamic brothers! From the above-mentioned blessed Ahadees it has become obvious that if the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم had wanted, he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم could have changed the timing of ‘Isha Salah, then offering Isha Salah before midnight or one third part of the night would not be permissible. Similarly, if Miswak had been declared Fard during Wudu, then Salah would not be valid without Miswak. (Mirat-ul-Manajih, vol. 1, pp. 280) But he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم did not do them for the ease of his Ummah.

Remember! The blessed Miswak is a very beautiful Sunnah of our Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم.

Umm-ul-Mu’mineen Sayyidatuna ‘Aaishah Siddiqah رَضِیَ اللهُ تَعَالٰی عَنْهَا has narrated:
اَنَّ النَّبِیَّ صَلَّی اللہُ عَلَیْہِ وَسَلَّمَ کَانَ اِذَا دَخَلَ بَیْتَہُ بَدَاَ بِالسِّوَاکِ i.e. Whenever the Beloved Rasool              صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم would come home, he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم would first use Miswak. (Sahih Muslim, pp. 124, Hadees 253)

And whenever he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم would rest during the day or night, then after waking up, he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم would use the blessed Miswak before Wudu. (Abu Dawood, vol. 1, pp. 54, Hadees 57)