When it comes to formal or legal documents, using the same phrase repeatedly can make the text seem monotonous and redundant. Instead, one can use synonyms for the phrase "we hereby acknowledge" to add variety and precision. Some of these synonyms include "we confirm," "we recognize," "we admit," "we accept," and "we declare." Each of these phrases has a slightly different connotation, so choosing the right one will depend on the context and purpose of the document. Overall, using synonyms can make text more engaging and effective in conveying the intended message.