Attestations of a term transliterated as brt appear in Egyptian monumental royal texts.
 

In temple regulations (Nauri decree of Sethy I) this term is used to describe how temple personnel are protected from being transported to other positions, one of which is


​𓅓𓃀𓅡𓄿𓂋𓏺𓍘𓇋𓅓𓃀𓎛𓅱𓏲𓂡 

in    brt                     of   labor

"m brt m bḥw,meaning 'under a brt (contract) of labor.' 
This labor type is mentioned alongside agricultural labor positions (plowing, harvesting). 

In an inscription dealing with the Second Libyan War dated to Ramses III's 11th Year (at Medinet Habu) another possible meaning appears relating to the state of troops attacked by the Egyptians:

𓁹𓇋𓇋𓈖𓏥      𓃀𓅡𓂋𓍘𓏤𓇋𓀁 𓂋𓎛𓈖𓂝 [                                                  ]

made-we   brt                      with

"ı͗r(y)⸗nw brt r-ḥnꜥꜥ" , 'we made a brt with..  ([to destroy] us), Egypt is eternally victorious...)' 

Another occurrence in the same texts describes how after the foreign troops were intimidated and confused, they:
 

𓁹𓇋𓇋𓏲𓏥        𓃀𓅡𓂋𓏺𓍿𓀁𓂋𓇥𓂋𓅱𓏛𓏥𓌨𓂋     𓏎𓋔𓏌𓏲𓏛𓏥𓊃𓈖𓏪

they-made  brt                     entirely          under tribute-their
"ı͗r(y)⸗w brt r-ḏrw ẖr ı͗n.w⸗sn"  

'(they were intimidated, enfeebled and confused) and they all made a brt , bearing their tribute (upon their backs)'.. 

Medinet Habu pl 82 line 28 brit.PNG

𓃀𓅡𓄿𓂋𓏺𓍘𓇋𓂡
𓃀𓅡𓄿𓂋𓏺𓍘𓇋
𓃀𓅡𓂋𓏺𓍿𓀁
𓃀𓅡𓂋𓏤𓍘𓇋𓀁
B-R-T *
ברית? מה זה?
 

*birītu, *birīta, *berītu

b-r-t are the consonants of a word attested in Egyptian texts
and
referencing a form of social agreement.

petrie stela brit PN f.PNG
brt.png

Photo credits

University of Chicago. 1932. Later historical records of Ramses III. Chicago: University of Chicago Press. Pls. 82-83. 

Griffith, F. Ll.  1927. 'The Abydos Decree of Seti I at Nauri.' The Journal of Egyptian Archaeology 13 (3/4): 193-208.

Petrie, F. 1925. Tombs of the Courtiers and Oxyrhynkhos. London. Pl. 31, no. 2.

References

Görg, M. 1979. “Bericht über die Arbeit an einem Wörterbuch der semitischen Fremdwörter im Ägyptischen,” in: W.F. Reineke (ed.), Acts of the First International Congress of Egyptology, Berlin: Schriften zur Geschichte und Kultur des Alten Orients, 237-41.

Kitchen, K. A. 1979. 'Egypt, Ugarit, Qatna and covenant.' Ugarit-Forschungen 11: 453-464.

Warburton, D. A. 1997. State and economy in ancient Egypt: fiscal vocabulary of the New Kingdom. Orbis Biblicus et Orientalis 151. Freiburg (Schweiz); Göttingen: Universitätsverlag; Vandenhoeck & Ruprecht.

David, A. 2006. Syntactic and lexico-semantic aspects of the legal register in Ramesside royal decrees. Wiesbaden: Harrassowitz , pp. 45, 49.