TAWHÎD - توحيد
Literally: Oneness. Unity.
It declares absolute monotheism: The unity and uniqueness of Allah as the creator and sustainer of the universe. To believe that there is no Ilah But Allah (‘Azza wa jalla). To know, understand and accept that there is no effect and dominance of anything, anywhere, and acting upon that idea and belief. To repeat the statement of tawhîd, which is لاَ اِلهَ اِلاَّ اللّٰهُ .
The statement of tawhîd is repeated in these âyahs of Qur’an: (37:359) (47:19)
Tawhîd is the opposite of Shirk.
“It is because of this mighty mystery that the Qur'an of Miraculous Exposition repeatedly and fervently and with elevated eloquence teaches tawhîd and Fardiyyah. Similarly, all the prophets, asfiyâ, and awliyâ found all their greatest pleasure and happiness in the statement of tawhîd, لاَ اِلهَ اِلاَّ اللّٰهُ ” The Flashes ( 423 )
“It is because Ilahî beauty and perfection are to be seen with the heart in the tawhîd and perceived by the rûh that all awliyâ and asfiyâ have found their sweetest zawq and most delectable ma’nawî rizq in dhikr of لاَ اِلهَ اِلاَّ اللّٰهُ , the statement of tawhîd. And it is because grandeur of magnificence, glory of Subhân, and the absolute sovereignty of the Rubûbiyyah of As-Samad are realized in the statement of tawhîd that Ar-Rasûl Al-Akram ‘Alayhissalâtu Wassalâm declared: اَفْضَلُ مَا قُلْتُ اَنَا وَالنَّبِيُّونَ مِنْ قَبْلِى لاَ اِلهَ اِلاَّ اللّٰهُThat is: The most precious word with fadhîlah, I and the prophets before me have said is لاَ اِلهَ اِلاَّ اللّٰهُ ” The Rays ( 17 )
“Indeed, like Imam al-Â’dham1 said that لاَ اِلهَ اِلاَّ اللّٰهُ is the mark and name of the tawhîd.” The Letters ( 401 )
“The fact that ahl al-îmân, and particularly those ahl al-tarîqah, are constantly repeating لاَ اِلهَ اِلاَّ هُوَ and recalling and proclaiming tawhîd, is an indication that tawhîd comprises many degrees. And also tawhîd is moreover a most important and a most enjoyable and a most exalted sacred, fıtrî duty and an ‘ibâdah of îmân. Let us then in order to attain a further degree, open the door of another stopping-place in this abode of instruction. For the true tawhîd, we seek is not a ma’rifat to be composed of tasawwur. Indeed, it is an affirmation called ‘ilm which is deemed equivalent to tasawwur in terms of logic and is more valuable than ma’rifat based on tasawwur and is the result of proof. And tawhîd al-haqîqî is such a judgement, an affirmation, an idh'ân and acceptance that one can find his Rabb through each thing, and see a path leading to his Khâliq in all things, and nothing can be an obstacle to his hudhur. For otherwise, it would always be necessary to tear and cast aside the veil of the universe in order to find his Rabb.” The Rays ( 175 )
KNOW that the Name “Allah” indicates and necessitates the meaning of all Asmâ Al-Husnâ and all attributes of Kamâl (Perfection) unlike other proper names of all other beings which point only to the beings themselves called by those names. Through the mystery of their attributes not being indispensable to them, their proper names do not point to their attributes. However, The Most Pure and Holy One’s (Dhât Al-Aqdas) Essence, Names and attributes are indispensable to each other. Also, since the proper Name “Allah” requires ulûhiyyah, it necessarily indicates all attributes. The word اِلهَ , which is used in the phrase 2 لاَ اِلهَ اِلاَّ اللّٰهُ before the rejection of all other things to which ulûhiyyah is attributed, also necessarily indicates all attributes.
If you understand this, you can understand thatلاَ اِلهَ اِلاَّ اللّٰهُ contains Tawhîd and all requirements and conclusions of Tawhîd to the number of Al-Asmâ Al-Husnâ. This single phrase contains thousands of phrases. Also, all the phrases it contains are combined from confirmation and negation. Since by being directed to each individual, the negation totally comprehends all the individuals of a compound, through the established principle of the Logic, there will be confirmations to the number of all the negations. Therefore, when لاَ اِلهَ اِلاَّ اللّٰهُ is said, from that negation all the confirmations like 3 لا خالق، ولا رازق، ولا قيّوم، ولا مالك، ولا فاطر، ولا قهار، إلّا اللّٰه emerge. Therefore, the meaning of the phrase لاَ اِلهَ اِلاَّ اللّٰهُ can be opened for a progressive dhâkir in all levels and ranks according to all degrees and states of those ranks. Then repeating this phrase becomes corroboration for confirmation.
Al-Mathnawî Al-Nûrî 573-574