[Another interpretation of (Psalms 32:6) AT A TIME OF FINDING:] That a person must keep hoping for a thing until he knows its end. Who was this? This was Jacob. Even though he said (Genesis 37:33), "Joseph has surely been torn to pieces," he was hoping in the Holy One, blessed be He. In the end He made known to him that Joseph was alive. And not only that, but He brought him the good news that he was alive: (Genesis 43:14) "And may God Almighty grant you mercy."
Jacob Hopes in God Until Joseph Is Found Alive
Midrash Tanchuma Buber, Miketz 15:3
[ד"א לעת מצוא], שאדם צריך להיות מקוה לדבר שידע סופו, מי היה זה, זה יעקב, אעפ"י שאמר טרוף טורף יוסף מחכה היה להקב"ה, בסוף הודיעו שיוסף חי, ולא עוד אלא שבישרו שהוא חי, ואל שדי יתן לכם רחמים.