Imam Jaffar described how verse 155 of Surat al-Baqara contains references to Hazrat Mahdi (as)

From Muhammad ibn Muslim: Imam Jaffar Sadik said: there will be signs before the appearance of the Qaim: Scourges will be visited upon believing servants by Almighty Allah. What are these signs? I asked. He replied: This is the word of Allah, May He be honored and glorified.

“We will test you with a certain amount of fear and hunger and loss of wealth and life and fruits. But give good news to the steadfast.” (Surat al-Baqara, 155)HE SAYS: WE WILL CERTAINLY TEST BELIEVERS. ... AND WITH HUNGER, IN OTHER WORDS WITH HIGH PRICES. LOSS OF WEALTH, BUSINESS STAGNATING AND A DECLINE IN PROSPERITY. LOSS OF LIFE, IN OTHER WORDS, QUICK AND SUDDEN DEATHS. LOSS OF FRUITS, IN OTHER WORDS, A DECLINE IN AGRICULTURE AND FRUITS LOSING THEIR FERTILITY. BUT TELL THE STEADFAST OF THE COMING OF THE QAIM. THEN HE TOLD ME: O MUHAMMAD! THIS IS THE TRUE INTERPRETATION.Allah, may He be honored and glorified, says: “Only Allah and those with deep knowledge know its meaning.” (Sheikh Muhammad ibn Ibrahim Numani, al-Ghaybah al-Numani)