This evidence is admissible because it is not hearsay.
Explanation:
Evidence is a confirmation document that is prepared and presented in the support of an assertion. This support may be strong or weak. The direct proof of the truth of an assertion is considered as strongest type of evidence.
A witness happened to see a defendant who involved in bank robbery. He saw the defendant was buying some groceries and paying money for it by removing a large roll of money. The witness questioned the defendant about his money and immediately the defendant nodded. This was considered as evidence as it is not hearsay.