There are basically two distinct views on Sufism and the connection to Islam. Some reject Sufism and consider it not being part of Islam, while others say as long as it follows the Qur'an and sunnah it is part of Islam.
Most Sufis consider themselves as applying al-Ihssan الإحسان as defined in the hadith of Jibreel which was narrated on the authority of abu Hurariah, abu Dharr, 'Umar ibn al-Khttab and other sahabah:
The man again asked, "O Allah's Messenger (ﷺ) What is Ihsan (i.e. perfection or Benevolence)?"
The Prophet (ﷺ) said, "Ihsan is to worship Allah as if you see Him, and if you do not achieve this state of devotion, then (take it for granted that) Allah sees you." ...
(See for example here in Sahih al-Bukhari, in Sahih Muslim, in Sunan an-Nasa-i, in Sunan abi Dawod, Sunan ibn Majah and Jami' at-Tirmidhi)
I'd like to know if any scholar has ever tried to verify statements or teachings of Sufis based on the Qur'an and sunnah.
For example is there any book or attempt that verifies the 264 Hikam (words of wisdom or aphorisms) of ibn 'Ata' Allah ابن عطاء الله السكندري also known as al-Hikam al-'Ataiyyah (here ENG/AR edition) الحكم العطائية based on the teachings of the Qur'an and sunnah?
As far as I know all known commentaries on These aphorisms are scholars who are also known to be sufis.
The aphorisms are hardly comprehensive and rather cryptic so that one couldn't understand them without further Information.