Is the expression "Allah is the founder of the Salafy Da'wah", correct?
Verily the Religion with Allah is Islaam, thus Islaam is (the only) Religion (accepted by) Allah and that which Allah legislated and sent down upon His messenger and servant ﷺ. Islaam is the seal of all divine legislations and religions. The followers of Islaam are Muslims who (should) not deviate from the straight path by way of innovation, misguidance or lowly degenerative desires. Now in response to those who have changed and substituted (aspects of their Religion with innovation, Misguidance etc.; the Muslims who have remained on the straight path) have been referred to and called: Ahlus Sunnah, Ahlus Sunnah Wa Jama'aah, Ahlul Hadeeth and the Salafies.
Thus, Salafiyyah is a noble affiliation and connection which means that they are on the way of the Salaf As Saalih (namely) the companions and those who come after them, who are upon their way. So this "nickname" (Salafy) distinguishes (the people of the Sunnah) from the people of Bid'ah (innovation) who have changed, substituted and altered (aspects of their religion). Furthermore, this expression, "Allah the founder of the Salafy Da'wah" means that Allah is He Who has legislated it; this is correct (in meaning) as was afore mentioned. However, to refer to Allah with the term "founder" is not permissible, because there is no text in which this (name) is mentioned. The principle is that we do not refer to Allah with names and attributes except for those which Allah (Subhaanah) affirmed for Himself or that which His messenger ﷺ affirmed for Him.
This (issue) is similar to the statement of some of them, "The engineer of the universe is Allah;" what is meant is that Allah is the Creator and this is correct from the standpoint of its meaning but prohibited from the standpoint of the expression itself. So with this, it is not permissible to use these two expressions due to that which was mentioned. All success is with Allah and may the peace and blessing be upon our Prophet Muhammad ﷺ.