Apex domains cannot have CNAME records.
Question and response
Question
dig mobily.com.sa. NS
Answer
mobily.com.sa. 4 NS dns1.mobily.com.sa.
mobily.com.sa. 4 NS dns2.mobily.com.sa.
Authority
The response has no authority records.
Additional
dns1.mobily.com.sa. 4 A 86.51.32.52
dns2.mobily.com.sa. 4 A 86.51.33.52
dns1.mobily.com.sa. 4 AAAA 2a02:ce0:1:20:0:0:0:9
dns2.mobily.com.sa. 4 AAAA 2a02:ce0:1:80:0:0:0:9
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0