Beraishit 34.31- בראשית

31.’And these are the kings who reigned in the land of Edom, before there reigned a king over the Children of Israel- וְאֵלֶּה הַמְּלָכִים אֲשֶׁר מָלְכוּ בְּאֶרֶץ אֱדוֹם לִפְנֵי מְלָךְ מֶלֶךְ לִבְנֵי יִשְׂרָאֵל (5001+11 words=5012=8 counting final Zadik, Mems and Kafs as 900, 600 and 500).

Rashi comments here that these eight kings of Edom correspond to the first eight Kings of Israel who defeated the Kingdom of Edom and appointed governors over them (1 Samuel 14.47; 2 Samuel 8.14; 1 Kings 22.48). 

The first Eight Kings of Israel/Judah were:

1.       Saul-                                    שאול = 337

2.       David-                                     דוד= 14

3.       Solomon-                           שלמה= 375

4.       Rehoboam-                     רחבעם = 320

5.       Abijah-                                 אביה =18

6.       Asa-                                       אסא = 62

7.      Yehosaphat-                   יהושפט = 410

8.       Yoram-                                  יורם = 256

1792+8 words=1800

Rashi adds here that in the days of Yoram- יורםthe son of Yehoshaphat, Edom revolted from the domination of Judah and crowned a king overthemselves (2.Kings 8.20). Rashi includes Saul’s son Ish-Boshet-איש בשת as one of the eight kings but he was not a de-facto king as David had been anointed in place of King Saul. This is proved by the above gematria.

The First 8 Kings of Israel/Judah=1800!