Kavyalankarasarasamgraha 5.75

5.75

pūrvapadaprakṛtisvareṇādyutāttatvāt /
hitapradetyasya tu (pā. a. 6 / 2 / 144) yathādisvareṇāntodāttatvāt /
tenātra svarabhedaḥ /
asvāpeti akārasya phalalubdhe iti ca ekārasya ubhayoḥ pakṣayoryathāyogaṃ lāghavālāghavābhyāṃ prayatnabhedo 'pi /
atastantreṇoccārayitumaśakyatā /
ekasmiṃstvatra śabde samuccarite śabdāntarasya tatsādṛśyātpratipattiḥ /
ato 'yaṃ śabdaśleṣaḥ /

while hitapradā has an acute accent on the final syllable according to the rule governing words ending in yathā, etc. (Pāṇini 6.2.144). / Therefore, there is a difference in accent here. / Moreover, regarding the short a in asvāpa and the e in phalalubdhe, there is also a difference in effort between the two sides respectively, owing to lightness and non-lightness. / Hence simultaneous pronunciation is impossible. / But when one word is pronounced here, another word is apprehended on account of its similarity to it. / Therefore, this is a verbal double meaning.