When the practice of sacrificing thoughts falls away, the creative right hemisphere is left barren, and that emptiness is the abomination that makes desolate: seeing at last that one's own mind has gone spiritually dry. The daily sacrifice is the steady offering of thought in meditation, each stray movement laid down so the inner ground stays alive.
Take that away and the true garden withers. The number 1290 measures the length of that barrenness, the counted stretch a person passes through once the discipline stops. What ends is the daily quieting of the mind that kept the creative side fruitful.
Daily sacrifice: the steady offering of thoughts laid down in meditation to keep the mind alive
Abomination that maketh desolate: the creative right brain gone barren, the mind seen as spiritually dry
1290 days: the measured span of that inner desolation once the discipline of meditation stops