The Prophet sallahu alayhi wa salam said:
وَقَالَ ” عَلاَمَ يَقْتُلُ أَحَدُكُمْ أَخَاهُ أَلاَّ بَرَّكْتَ اغْتَسِلْ لَهُ
Why does one of you kill his brother? Why did you not say, “May Allah bless you?” Do ghusl for it.
Ibn Abdul-Barr rahimahullah in al-Istadhkaar: ” His statement sallahu alayhi wa salam: “Why did you not say, “May Allah bless you?” indicates that the one who likes something and says: “Tabarakallahu Ahsanul Khaliqeen, Allahumma Baarik fihi” or the likes of this, then he will not harm it [the thing he likes] inshallah”
And he said rahimahullah in at-Tahmeed: “at-Tabreek is for a person to say: Allahummah Baarik fihi” or the likes of this. It was said that at-Tabreek is to say: “Tabarakallahu Ahsanul-Khaliqeen Allahumma Baarik fihi”
This statement: “Tabarakallahu Ahsanul-Khaliqeen Allahumma Baarik fihi” was mentioned by more than one scholar of the past, but I did not find any proof for it.
Ibn al-Qayyim said in Zaad al-Ma’ad: “if the one who gives the evil eye fears harm due to his eye, then let him remove the harm by his statement: Allahumma Baarik ‘alahi as the Prophet sallahu alayhi wa salam said to ‘Aamir ibn Rabi’ah when he saw Sahal ibn Hunaif. He said: Why did you not say, “May Allah bless you…”
Although Shaikh Ibn ul-Uthaymeen rahimahullah said that, “if a person sees what he likes and fears envy and the evil eye, then verily he should say: Ma shallah Tabaarkallah”
[Noor ‘ala Darb]
[Taken from here]
Faisal Ibn Abdul Qaadir Ibn Hassan
What is more correct is what Imam Ibn Qayyim argues because it is closer to the Hadith of Sahal. And Allah knows best
~ Faisal Ibn Abdul Qaadir Ibn Hassan